Date post: | 13-May-2018 |
Category: |
Documents |
Upload: | truongdiep |
View: | 218 times |
Download: | 2 times |
Data Gathering for requirements and evaluations
1
Lecture 3
Slides adapted byDr. Kristina Lapin
Vilnius University
Projektas Informatikos ir programų sistemų studijų programų kokybės gerinimas ( VP1-2.2-ŠMM-07-K-02-039)
2www.id-book.com
Overview
Five key issues of data gathering
Data recording
Interviews
Questionnaires
Observation
Choosing and combining techniques
Participative design
• Requirements are gathered while communicating with project stakeholders
–A result of communication: user stories
• Generalized similar user stories help:
– to define conceptual scenario of the developed product
–generate the requirements
3
Prioritizing requirements
• Must have
– fundamental requirements
• Should have
–essential if more time were available,
• Could have
–of lesser importance,
• Want to have
–but Won’t have this time round
4Adapter from www.id-book.com
Sources of design ideas
• Lead users
–Adapted current technologies to their needs
• Technophobes
–why they do not use current systems
5
Von Hippel, E. (1986). Lead users: a source of novel
product concepts. Management science, 32(7), 791-805.
7Adapter fromwww.id-book.com
Five key issues
1. Setting goals
• Decide how to analyze data once collected
2. Identifying participants
• Decide who to gather data from – the population
• Probability sampling and non-probability sampling
• Saturation sampling – access to all members
8Adapter fromwww.id-book.com
Five key issues
3. Relationship with participants• Clear and professional
• Informed consent when appropriate
4. Triangulation• Look at data from more than one perspective
5. Pilot studies• Small trial of main study
10Adappter fromwww.id-book.com
Data recording
• Notes, audio, video, photographs
– Choice depends on the context, time available and the sensitivity of the situation.
• Notes plus photographs
– Handwritten notes – flexible and less intrusive than typing,
– Can be tiring to write, observe and listen at the same time
• Audio plus photographs
– Audio – less intrusive than video
– Attention to the interviewee rather than to taking notes
• Video
– Requires additional planning
What to choose?
• Imagine you are employed to develop a new computerized garden system planning tool to be used by garden designers.
• Goal: to find out
– how garden designer use an early prototype as they walk around their clients’ gardens
– sketching design ideas, taking notes and asking the clients about
– what they like and how they use the gardens
• What are the advantages and disadvantages of the 3 approaches to data recording in this environment?
11
Criterion
Notes plus camera Audio plus camera Video
Equipment
Paper, pencil, and camera are easily available
Inexpensive, hand-held recorder with a good microphone
More expensive. Editing, mixing, and analysis equipmemnt needed
Flexibility of use
Very flexible.Unobtrusive.
Flexible. Relatively unobtrusive.
Needs positioning and focusing camera lens. Obtrusive.
Completeness of data
To get what note taker thinks is important and can record in the time available. Problem with unexperienced evaluators.
Complete audio recording but visual data is missing. Notes,photographs, sketches augment recording butneed coordinating
Most complete data, especially if more than one camera is used, but coordination of video material is needed.
Disturbance of users
Very lowLow, but microphone needs to be positioned.
Medium. Camera needs to be positioned. Care needed to avoidHawthorne effect.
Reliability of data
May be low. Relies on making a good record and knowing what to record.
High but ecternal moise, e.g. Fans in computers, can mffle what is sad
Can be high but depends on what camera is focused on
Analysis
Rich descriptions can be produced.
Critical discussions can be identified.
Critical incidents can be identified and tagged.
13www.id-book.com
Interviews
• Conversation with a purpose
• Unstructured
– are not directed by a script. Rich but not replicable.
• Structured
– tightly scripted, often like a questionnaire.
– Replicable but may lack richness.
• Semi-structured
– guided by a script• but interesting issues can be explored in more depth.
• Can provide a good balance between richness and replicability.
• Group interviews
14www.id-book.com
Interview questions• Two types:
− ‘closed questions’ have a predetermined answer format, e.g., ‘yes’ or ‘no’
− ‘open questions’ do not have a predetermined format
• Closed questions are easier to analyze
Avoid:
− Long questions
− Compound sentences - split them into two
− Jargon and language that the interviewee may not understand
− Leading questions that make assumptions e.g., why do you like …?
− Unconscious biases e.g., gender stereotypes
Focus groups
• Frequently used in marketing and political campaigning.
• 3-10 people involved and discussion is led by trained facilitator
– Participants are selected to provide a representative sample of the target population
• Benefit: diverse or sensitive issues can be raised investigating community issues
• Drawback: what they say is not always what they do
19
Focus group: problems
• Whar they say is not always what they do
–People sometimes give the answers that they think show them in the best light
–They may forget how long they spend on a particular activity
• So, can we believe all the responses we get?
20
Planning and conducting an interview
• Developing interview questions
–Open – for exploratory sessions
–Closed – when the possible answers are known in advance
– structured interview usually consists of open questions,
–while a structured – closed
–Semistructured – a combination of both
21Adapter from www.id-book.com
Example
• How appealing are reading devices to people over 65?
22
Sony e-readerAmazon Kindle Apple iPad
Data gathering session
• The goal: to seek opinions whether e-readers would appealing to people over 65
• Suggest ways od recording the interview data.
• Suggest set of questions.
23
Data gathering session
• Based on results of unstructures interview developers have found that two important acceptance factors are:
–whether the device can be handled easily;
–whether the typeface and appearance can be altered.
25
An introduction
• Interviewer introduces hweself, explains why the interview is being done, reassures interviewees regading any ethical issues, asks if they mind being recorded
A warm-up session
• Non-threatening questions, i.e. Demographic information
A main session
• Questions presented in logical sequence
A cool-off period
• Qa few easy questions to defuse tension if it has arisen
A closing session
• The interviewer than ks for the interviewee;
• Switches off the recorder or puts the notes away signaling that the interview has ended
Running the interviu
26
Other forms of interview
• Telephone interviews
– Much in common with face-to-face but it is not possible to see the interviewee’s body language or facial expressons
• Online interviews
– Emails, chats, video conferencing
• Retrospective interviews
– Reflects on an activity or a data gathering session in the recent past
– May be conducted to check that the interviewer has correctly understood what was happenning
27
28Adapted fromwww.id-book.com
Enriching the interview process
• Neutral meeting room
• Props - devices for prompting interviewee,
– e.g., a prototype, scenario
29www.id-book.com
Questionnaires
• Questions can be closed or open
• Closed questions are easier to analyze, and may be done by computer
• Can be administered to large populations
• Paper, email and the web used for dissemination
• Sampling can be a problem
– when the size of a population is unknown as is common online
Questionnaire structure
1. Many start by asking for basic demographic information
–Gender, age, place
30
32www.id-book.com
Questionnaire design
• The impact of a question can be influenced by question order.
• Do you need different versions of the questionnaire for different populations?
• Provide clear instructions on how to complete the questionnaire.
• Strike a balance between using white space and keeping the questionnaire compact.
• Decide on whether phrases will all be positive, all negative or mixed.
33www.id-book.com
Question and response format
• ‘Yes’ and ‘No’ checkboxes
• Checkboxes that offer many options
• Rating scales
– Likert scales
– semantic scales
– 3, 5, 7 or more points?
• Open-ended responses
35www.id-book.com
Encouraging a good response
• Make sure purpose of study is clear
• Promise anonymity
• Ensure questionnaire is well designed
• Offer a short version for those who do not have time to complete a long questionnaire
• If mailed, include a stamped addressed envelope
• Follow-up with emails, phone calls, letters
• Provide an incentive
• 40% response rate is high, 20% is often acceptable
Quality of a good question
1. Evokes the truthNon-threatining questions
For sensitive questions clearly state policy ofconfidentiality
2. Asks for an answer on only one dimension.
Do you like the texture and flavor of the snack?
36Adapter from www.id-book.com
Quality of a good question (2)
3. Accommodate all possible answers
37
What brand of computer do you own? Apple IBM PC
Do you own IBM PC? ○ Yes○ No
What brand of computer do you own? (Check all that apply) Do not own computer IBM PC Apple Other
Quality of a good question (3)
4. Has mutually exclusive options
5. Produces variability of responses
38
Where did you grow up? Country Farm City
What do you think about this report?A. It's the worst report I've readB. It's somewhere between the worst and bestC. It's the best report I've read
Quality of a good question (4)
6. Follows comfortably from the previous question
7. Does not presuppose a certain state of affairs.
39
Are you satisfied with your current auto insurance? (Yes or No)
http://www.statpac.com/surveys/question-qualities.htm
Quality of a good question (5)
8. Does not imply a desired answer.
9. Does not use emotionally loaded or vaguely defined words
10. Does not use unfamiliar words or abbreviations.
40
e.g. most, least, majority
http://www.statpac.com/surveys/question-qualities.htm
What was your AGI last year? ____
Quality of a good question (5)
11. Is not dependent on responses to
previous questions.
12. Does not ask the respondent to order or rank a series of more than five items
41
1. Do you currently have a life insurance policy? (Yes
or No) If no, go to question 32. How much is your annual life insurance premium?__
http://www.statpac.com/surveys/question-qualities.htm
Administering questionnaires
• Issues
– Reaching a respresentative sample
– Ensuring a resonable response rate
• For large surveys
– Respondents are selected using sampling techniques
• Interaction designers commonly use small samples, less that 20 users
• 40% response rate is good
– Much lower rates are common
43
44www.id-book.com
Advantages of online questionnaires
Responses are usually received quickly
No copying and postage costs
Data can be collected in database for analysis
Time required for data analysis is reduced
Errors can be corrected easily
45www.id-book.com
Problems with online questionnaires
Sampling is problematic if population size is unknown
Preventing individuals from responding more than once
Individuals have also been known to change questions in email questionnaires
Postcard used as a ‘cultural probe’.
Source: Gaver, W.W., Dunne, T. and Pacenti, E. (1999) Cultural Probes, Interactions, 6(1), pp. 21–29. © 1999 ACM, Inc.
From Benyon, Designing interactive systems, Pearson Education, 2005.
Probes
• collections of artefacts designed
to elicit requirements, ideas or
opinions in specific contexts
– Cultural probes developed to uderstand way of life of elderlypeople in different countries
– Technology probes were usedto gather requirements forhome technologies
Card sorting
• Refers to a number of techniques concerned with understanding how people classify and categorize things.
47Adapter fromwww.id-book.com
Card sorting
• Open card sorting
– starts with blank cards, participants are asked to write down the objects or actions they think are important in some domain.
–These are then gathered together into categories
• Closed card sorting
– starts with predefined categories and asks participants to place objects into the categories
48Adapter fromwww.id-book.com
53Adapter from www.id-book.com and Benyon,
Observation
• Direct observation in the field
– Structuring frameworks
– Degree of participation (insider or outsider)
– Ethnography
55www.id-book.com
Structuring frameworks to guide observation
• - The person. Who? - The place. Where?- The thing. What?
• The Goetz and LeCompte (1984) framework:- Who is present? - What is their role? - What is happening? - When does the activity occur?- Where is it happening? - Why is it happening? - How is the activity organized?
64www.id-book.com
Choosing and combining techniques
• Depends on
– The focus of the study
– The participants involved
– The nature of the technique
– The resources available
65www.id-book.com
Summary• Three main data gathering methods:
– interviews, questionnaires, observation
• Five key issues of data gathering: – goals, choosing participants, triangulation, participant
relationship, pilot
• Interviews may be – structured, semi-structured or unstructured
• Questionnaires may be – on paper, online or telephone
• Observation may be – direct or indirect, in the field or in controlled setting
• Techniques can be – combined depending on study focus, participants,
nature of technique and available resources
References
• David Benyon, Phil Turner, Susan Turner. Designing Interactive Systems: People, Activities, Contexts, Technologies. Addison Wesley, 2005, 2014. chapter 7: Understanding
• Qualities of a good question
66Adapter fromwww.id-book.com